/Engine/Source/Runtime/Engine/Classes/Engine/AssetManager.h
This will expand out references in the passed in AssetBundleData that are pointing to other primary assets with bundles. This is useful to preload entire webs of assets
virtual void RecursivelyExpandBundleData ( [FAssetBundleData](API\Runtime\CoreUObject\AssetRegistry\FAssetBundleData) & BundleData ) const